A shooting at YouTube's headquarters in San Bruno, Calif., left four people injured and one person dead of an apparent self-inflicted gunshot wound Tuesday, police said.

San Bruno police Chief Ed Barberini told reporters that first responders found four gunshot victims inside the building and at an adjacent building.

There was also one woman inside the YouTube building with what investigators believe is a self-inflected gunshot wound, a person "we believe to be the shooter," Barberini.

Representatives from San Francisco General Hospital and Stanford University Hospital told KPIX-TV in San Francisco that they received patients from the incident.

Shortly after police received 911 calls about the shooting at 12:46 p.m., San Bruno police tweeted they were responding to an "active shooter" and ordered the public to stay away from the area near Cherry Avenue and Bay Hill Drive.

Google, the parent company of YouTube, said it was coordinating with law enforcement and hospitals.

"Our Security team has been working closely with authorities to evacuate the buildings and ensure the safety of employees in the area," the company said.

YouTube employees said they were barricaded inside their offices at the company's San Bruno, Calif., headquarters Tuesday as police responded to an "active shooter" at the building.